Sahlins' work has focused on demonstrating the power that culture has to shape people's perceptions and actions. He has been particularly concerned to demonstrate that culture has a unique power to motivate people that is not derived from biology. His early work focused on criticizing the idea of "economically rational man" and to demonstrate that economic systems adapted to particular circumstances in culturally specific ways. After the publication of Culture and Practical Reason in 1976, his focus shifted to the relation between history and anthropology, and the way different cultures understand and make history. Although his focus has been the entire Pacific, Sahlins has done most of his research in Fiji and Hawaii.

"The world's most 'primitive' people have few possessions, but they are not poor. Poverty is not a certain small amount of goods, nor is it just a relation between means and ends; above all it is a relation between people. Poverty is a social status. As such it is the invention of civilization. It has grown with civilization, at once as an invidious distinction between classes and more importantly as a tributary relation."

In his Evolution and Culture (1960), he touched the areas of cultural evolution and neoevolutionism. He divided the evolution of societies into "general" and "specific". General evolution is the tendency of cultural and social systems to increase in complexity, organization and adaptiveness to environment. However, as the various cultures are not isolated, there is interaction and a diffusion of their qualities (like technological inventions). This leads cultures to develop in different ways (specific evolution), as various elements are introduced to them in different combinations and on different stages of evolution.[1][6]

In the late 1990s, Sahlins became embroiled in a heated debate with Gananath Obeyesekere over the details of Captain James Cook's death in the Hawaiian Islands in 1779. At the heart of the debate was how to understand the rationality of indigenous people. Obeyesekere insisted that indigenous people thought in essentially the same way as Westerners and was concerned that any argument otherwise would paint them as "irrational" and "uncivilized". In contrast Sahlins argued that each culture may have different types of rationality that make sense of the world by focusing on different patterns and explain them within specific cultural narratives, and that assuming that all cultures lead to a single rational view is a form of eurocentrism.[1]

In 2001, Marshall Sahlins became the executive publisher of a small press called Prickly Paradigm.

In 2011, a conference dedicated to the work of Marshall Sahlins was held at the Sorbonne in Paris.[7]

In 2013, on February 23, it was reported that Sahlins resigned from the National Academy of Sciences to protest the election of Napoleon Chagnon. The resignation follows the publication in that month of Chagnon's memoir and widespread coverage of the memoir, including a profile of Chagnon in the New York Times magazine.[8][9]

About the controversy with Obeyesekere (See also Death of Cook article, about the 2004 re-discovery of the original painting of the incident by John Cleveley the Younger, showing a less idealised Cook):